Background Disease-modifying therapies for RA have proven efficacy, but selective toxicities, such as malignancy, may increase with treatment duration. Periodic re-evaluation of incidence rates (IRs) allows assessment of any cumulative or new events over time.
Methods Data were pooled from the cumulative (double-blind and open-label short-term [ST] and open-label LT extension) periods of 13 Phase II and III studies.1,2 IRs of safety events were calculated as the number per 100 patient-years (pt-yrs) of exposure (Poisson 95% CI). IRs for the cumulative period were compared with IRs originally estimated from the pooled ST periods of eight IV ABA clinical studies.2
Results A total of 6028 pts received IV or SC ABA during the cumulative period (total exposure of 16,670.56 pt-yrs; 1167 pts received ABA for >5 years). IRs of adverse events (AEs), serious AEs (SAEs), infections or serious infections did not increase in the cumulative relative to ST periods (Table). The most frequently reported serious infections in the cumulative period were pneumonia (IR [95% CI]: 0.43 [0.34, 0.54]) and upper respiratory tract infection (0.18 [0.12, 0.26]). There was no increase in IRs between the ST and cumulative periods for hospitalised, opportunistic or tuberculosis infections. The IRs of overall malignancy, combined lymphomas and lung cancers did not increase in the cumulative versus the ST periods; the most common malignancies in the cumulative period were basal cell carcinoma (IR [95% CI]: 0.46 [0.36, 0.58]) and squamous cell carcinoma (0.15 [0.09, 0.22]). The IR of autoimmune AEs during the cumulative period was comparable to the ST period, the most common event being psoriasis (IR [95% CI]: 0.51 [0.40, 0.63]).
Conclusions Based on the cumulative ST and LT exposure of 6028 patients to IV or SC abatacept (16,670.56 pt-yrs), the IRs and events reported with LT abatacept treatment were similar to those reported in the ST, with no increase in rate for any event with increasing exposure. These findings demonstrate that IV and SC abatacept are both well tolerated over the LT.
Alten R et al. Arthritis Rheum 2011;63(10 Suppl):S150;
Hochberg M et al. Arthritis Rheum 2010;62(10 Suppl):S164.
Disclosure of Interest R. Alten Grant/research support from: BMS, Merck Pharma GmbH, Wyeth Pharmaceuticals, Pfizer, Consultant for: Abbott Laboratories, Horizon Pharma, Merck Pharma GmbH, Nitec Pharma GmbH, Novartis Pharmaceuticals Corporation, Roche, Speakers bureau: Abbott Laboratories, BMS, Horizon Pharma, Merck Pharma GmbH, Novartis Pharmaceuticals Corporation, Roche, M. Hochberg Grant/research support from: NIH, Consultant for: Abbott Laboratories, Amgen Inc., BMS, Eli Lilly and Company, EMD Serono Inc., Genentech/Roche, Merck & Co., Inc., Novartis Pharma AG, Pfizer Inc, Speakers bureau: Bioberica SA, IBSA, Rottapharm/Madaus, R. Cohen Consultant for: Bristol-Myers Squibb, M. Weinblatt Grant/research support from: Bristol-Myers Squibb, Consultant for: Bristol-Myers Squibb, Abbott, J. Kaine Grant/research support from: Bristol-Myers Squibb, Speakers bureau: Bristol-Myers Squibb, UCB, E. Keystone Grant/research support from: Abbott Laboratories; Amgen Inc.; AstraZeneca Pharmaceuticals LP;, Consultant for: Abbott Laboratories; AstraZeneca Pharma, Biotest, Bristol-Myers Squibb Company; F. Hoffmann-La Roche Inc; Genentech Inc; Jannsen Inc, Lilly Pharmaceuticals; Merck, Nycomed, Pfizer Pharmaceuticals, UCB, Speakers bureau: Abbott Laboratories; Astrazeneca LP, Bristol-Myers Squibb Canada; F. Hoffmann-La Roche Inc.; Janssen Inc.; Pfizer Pharmaceuticals, UCB, Amgen, Abbott Pharmaceuticals, P. Nash Grant/research support from: Bristol-Myers Squibb, Consultant for: Bristol-Myers Squibb, Speakers bureau: Bristol-Myers Squibb, I. Delaet Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, M. Genovese Grant/research support from: Bristol-Myers Squibb, Consultant for: Bristol-Myers Squibb